Brittany Nixon wins second place at NSF REU Presentation Contest!

LIMBS Lab summer REU student Brittany Nixon won Second Place out of 15 talks at the annual JHU / LCSR Summer REU Program for her excellent oral presentation entitled “A Mathematical Model of the Fish Tracking Response of the Weakly Electric Glass Knifefish”. Special thanks to her mentor Ismail Uyanik.

 

Left: A day in the lab. Right: Brittany & Ismail at Brittany’s poster the day before.

Brittany joins a long list of successful REU students from the LIMBS lab!

2010: Rohan Ramesh (1st Place), Rachel Jackson (2nd Place)
2012: Daniel Price (1st Place)
2016:  Luke Arend (1st Place)
2018: Brittany Nixon (2nd Place)

Virtual reality alteration of visual feedback in cerebellar patients can improve reaching

Amanda Edwards’s presentation at the OSU MBI Workshop: CONTROL AND MODULATION OF NEURONAL AND MOTOR SYSTEMS, September 12, 2017:

https://mbi.osu.edu/video/player/?id=4343

Abstract: People with damage to their cerebellum often exhibit “reaching ataxia”, or misdirected, poorly scaled movement patterns which are reminiscent of a poorly tuned control system. Ataxia affects most all activities of daily living (e.g. eating, cooking, bathing, dressing, working). It is believed that these patients have a static, miscalibrated internal model of their body dynamics; however, it is unknown whether their feedback control is intact. We challenged these participants with visuomotor system identification tasks in order to model their feedback control architecture. Our results suggest that cerebellar patients have intact feedback control, but are forced to rely on time-delayed visual feedback. The key difference is that healthy subjects seem to be able to compensate for their visuomotor delay suggesting that the cerebellum may be serving the role of a Smith predictor for this task. Finally, we were able to leverage the cerebellar patients intact visuomotor feedback control system to improve the scaling of these movements by altering their visual feedback based on their real-time movement in a virtual reality environment.

Introducing Dr. Erin Sutton!

On July 6, 2016, Erin Sutton successfully defended her PhD Dissertation “Bioelectric Sensing and Navigation: Multimodal Control in Electric Fish and Endovascular Interventions”, becoming the 10th PhD graduate of the LIMBS Laboratory.

Congrats Erin!

Demonstration of “Stabilizing an Unstable System”

In a recent talk at the CMU Robotics Institute, I decided to give a quick impromptu demonstration of what it means to “stabilize an unstable system,” thereby making it easier to apply system identification.  This was in relation to my presentation of my previous PhD student Manu Madhav’s paper:

 

M. S. Madhav, S. A. Stamper, E. S. Fortune, and N. J. Cowan. “Closed-loop stabilization of the jamming avoidance response reveals its locally unstable and globally nonlinear dynamics”. J Exp Biol, 216:4272-4284, 2013.

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